In the conventional sunroof for a vehicle for example, an apparatus for opening and closing a lid in the sunroof comprises a first transmission system for transmitting the rotational power of a drive motor to drive cables of the lid, and a second transmission system for transmitting the power to a rotary body provided with control surfaces for turning on and off detecting switches for detecting the opening and closing positions of the lid.
As disclosed in Japanese Laid-Open Patent No. 58-214414, the rotary body driven by the second transmission system is disposed on the axis of a drive shaft driven by a drive motor and a plurality of detecting switches are arranged in proximity to the control surfaces of the rotary body.
The rotary body is disposed on the axis of the drive shaft as mentioned above, and the rotary body and the respective switches, which are turned on and off by the control surfaces of the rotary body, are projected upwards from the casing of the apparatus, so that the height of the rotary body and therefore the thickness of the entire apparatus could become thick. In particular, the drive apparatus is desirably as thin as possible since the apparatus is disposed within a housing space between outer and inner panels of the roof. However, as the entire apparatus becomes thick as mentioned above, it is necessary to secure the increased housing space therefor so that the ceiling of the compartment must be lowered in height.
To solve this problem, it is considered to separately dispose a transmission gear in the first transmission gear system for transmitting the power to the drive cables of the lid and take out the power by engaging the separate transmission gear with the second transmission gear system. In such a structure, it is possible to reduce the thickness of the apparatus along the axis of the drive shaft, but a region for the separate transmission gear is increased in thickness since the separate transmission gear is disposed downward from the first transmission gear system. The region for the transmission gear is located at a place at which a discharging tray crosses in the widthwise direction of the vehicle and the thickness of the separate transmission gear is thus restricted, so that it is not desirable in structure to separately dispose such a transmission gear, and the height of the ceiling of the compartment could be reduced as mentioned above.
The plurality of detecting switches have switch terminals capable of contacting the control surfaces of the rotary body and are arranged around the rotary body for sliding and tilting the lid. In this case, it is necessary to position the respective detecting switches in predetermined positions in which the opening and closing positions of the lid are properly detected, and the respective detecting switches are attached into the apparatus while positioning the switches at predetermined places one by one. Therefore, the switches must be carefully attached and the assembly thereof is not easy and an error in assembly tends to be generated.
Further, in the conventional drive apparatus in which the lid is open and closed by moving the drive cables, a large load is applied to the drive motor when a foreign matter jams the lid and stops the operation of the lid. To solve this problem, as in Japanese Laid-Open Patent No. 58-214414, when the lid is stopped in an intermediate position between the opening and closing positions, the transmission path is interrupted by generating a slip therein by a frictional clutch so as not to apply an excessive load to the drive motor.
FIG. 1 shows the conventional drive apparatus in which a main shaft 103 is supported at both ends thereof by a casing body 101 and is slidable along the axial direction. A main gear 107 is engaged with a worm gear 105 which is an output gear of a drive motor. A driven gear 113 is connected to drive cables 109 of the lid through a transmission mechanism 111. The main gear 107 and the driven gear 113 are mounted on the main shaft 103. The main gear 107 is located between upper and lower clutch plates 106, 106 integral with the main shaft 103. A clutch spring 115 is disposed between the main gear 107 and the driven gear 113 to control the transmitted force therebetween. The driven gear 113 is integrally coupled to the main shaft 103.
In the apparatus shown in FIG. 1, the force transmitted to the driven gear 113 is controlled by adjusting the elastic pressure of the clutch spring 115. The elastic pressure of the clutch spring 115 is increased as the main gear 107 and the driven gear 113 approach each other, thereby increasing the coupling force of the clutch plate 106. The elastic pressure of the clutch spring 115 is decreased as the main gear 107 and the driven gear 113 are separated from each other, decreasing the coupling force of the clutch plate 106. The main gear 107, together with the main shaft 103, approach and are separated from the driven gear 113 in the axial direction by tightening and untightening a nut 119 screwed onto a screw portion 117 formed on the main shaft 103. In this case, it is necessary to fix the main shaft 103 so as not to be rotated when the nut 119 is rotated. Therefore, in the conventional apparatus, a tool engaging groove 125 is disposed in a gear shaft 123 spline-engaged with an intermediate gear 121, and the nut 119 is rotated while a tool 127 is inserted into the tool engaging groove 125 to prevent the rotation of the main shaft 103.
According to the conventional apparatus mentioned above, after the apparatus has been assembled, it is very complicated to adjust and set the elastic pressure of the clutch spring 115 to a predetermined value. Further, it is necessary to spline-fit the intermediate gear 121 and the gear shaft 123 to each other, and rotatably support both ends of the gear shaft 123 by bearings, which are unfavorable in processing and assembly.
Further, in the conventional drive apparatus having a control device for opening and closing the lid, the lid of the sunroof is open and closed when necessary, and a means for operating the sunroof must actuate the lid from various states thereof to a predetermined state which a user wants. However, in such means, it is generally necessary to perform complicated operations to selectively actuate the lid in a plurality of operating states and push a switch again in boundary states between the operating states in consideration of the present state of the lid.
In Japanese Laid-Open Patent No. 60-199183, another control device in the drive apparatus has been proposed to solve this problem. In this control device, the state of a lid is provided by a bit signal which is stored in a bit memory, and the operation of the sunroof is controlled in accordance with the stored data. The control device is provided with a backup power device for maintaining the bit memory in the stored state at any time such that the stored data are not deleted.
However, in such a conventional control device of the sunroof, the state of the lid is once stored as a bit signal in the bit memory and the operation of the sunroof is controlled on the basis of the stored memory so that the inputting and outputting of the bit information with respect to the bit memory are fundamentally complicated, thereby making it necessary to provide a complicated electrical means. Further, since the bit memory plays an important role in this control device, the backup power source is required to maintain the bit information so that the control device is complicated and expensive as a whole.